California Code, Government Code - GOV § 38793

As a means of implementing a municipal underground utility district formed to remove existing overhead utility lines and to require property owners of the district, served by such lines, to prepare their properties to accept underground utility lines, cities may provide by ordinance that if any property owner, after due notice, refuses to comply within a reasonable time to effect such removal or preparation in accordance with the applicable rules of the utility involved the city may cause such work to be done and assess the costs thereof against the property and that such assessment shall become a lien against the property.  The assessment may be collected at the same time and in the same manner as ordinary municipal ad valorem taxes are collected, and shall be subject to the same penalties and the same procedure and sale in case of delinquency as provided for such taxes.  All laws applicable to the levy, collection and enforcement of municipal ad valorem taxes shall be applicable to such assessment.